This invention is related to a substrate coated with a pigmented layer and a clear layer, hereinafter referred to as a color coat/clear coat, of high solids acrylic coating compositions.
Conventional coating compositions of a high molecular weight acrylic polymer and a melamine crosslinking agent are well known in the art as shown by Vasta U.S. Pat. No. 3,622,651, issued Nov. 23, 1971; Hick U.S. Pat. No. 3,841,895, issued Oct. 15, 1974; Parker U.S. Pat. No. 3,674,734, issued July 4, 1972 and Parker U.S. Pat. No. 3,637,546, issued Jan. 25, 1972. These patents illustrate good quality coating compositions that can be used for color coat/clear coat finishes. However, these compositions have a relatively high solvent content to provide for good application properties and for good properties of the resulting finish. To utilize these compositions in areas which have strict air pollution regulations, pollution abatement equipment is required. This equipment is expensive and increases capital investment of a plant and is costly to operate. Any attempt to reduce the solvent content of these conventional compositions generally results in finishes which have either a poor appearance or unacceptable physical properties or both.
There is a great need for a coating composition to form color coat/clear coat finishes that have a low solvent content and that will meet current air pollution regulations but still provides a high quality finish that is useful an an exterior finish for automobiles, trucks and airplanes. The high solids coating composition of this invention has these desirable characteristics.